Washington, June 16 (ANI): People with higher blood levels of vitamin B6 and the essential amino acid methionine (found in most protein) have a lower risk of lung cancer, according to a new study.

Paul Brennan, of the International Agency for Research on Cancer, Lyon, France, and colleagues conducted an investigation of B vitamins and methionine status based on serum samples from the European Prospective Inves­tigation into Cancer and Nutrition (EPIC) cohort study, which recruited 519,978 participants from 10 European countries between 1992 and 2000, of whom 385,747 donated blood.

By 2006, 899 lung cancer cases were identified and 1,770 control participants were individually matched by country, sex, date of birth, and date of blood collection.

After an analysis of the incidence rate of lung can­cer within the entire EPIC cohort and adjusting for various factors, the researchers found a lower risk for lung cancer among participants with increasing levels of B6 (comparing the fourth vs. first quartile of B6 levels). A lower risk was also seen for increasing methionine levels.)

"Similar and consistent decreases in risk were observed in never, former, and current smokers, indicating that results were not due to confounding [factors that can influence outcomes] by smoking. The magnitude of risk was also constant with increasing length of follow-up, indicating that the associations were not explained by preclinical disease," the researchers said.

When participants were classified by median (midpoint) levels of serum methionine and B6, having above-median levels of both was associated with a lower lung cancer risk overall. A moderate lower risk was observed for increasing serum folate levels, although this association was restricted to former and current smokers, and was not apparent in never smokers.

"Our results suggest that above-median se­rum measures of both B6 and methionine, assessed on average 5 years prior to disease onset, are associated with a reduction of at least 50 percent on the risk of developing lung cancer. An additional association for serum levels of folate was present, that when combined with B6 and methionine, was associated with a two-thirds lower risk of lung cancer," the authors said.

The study has been published in The Journal of the American Medical Association (JAMA). (ANI)